Poli-Sci Perspective is a weekly Wonkblog feature in which Georgetown University’s Dan Hopkins and George Washington University’s Danny Hayes and John Sides offer an empirical perspective on the issues dominating Washington.

This combination of undated file photos shows Tamerlan Tsarnaev, 26, left, and Dzhokhar Tsarnaev, 19. The CIA added the name of dead Boston Marathon bombing suspect Tamerlan Tsarnaev to a U.S. government terrorist database 18 months before the deadly explosions, U.S. officials told The Associated Press. (AP)

From the moment that Boston bombing suspect Dzhokhar Tsarnaev was pulled out of a boat in Watertown, Mass., the debate over civil liberties and domestic anti-terrorism policies, largely dormant in recent years, was reignited.

Noting that “the homeland is the battlefield,” Sen. Lindsey Graham (R-S.C.) urged the Obama administration to designate Tsarnaev, an American citizen, as an enemy combatant. Civil liberties groups then objected when authorities decided not to read Miranda rights to the Boston Marathon bombing suspect, invoking a public safety exception. Speculation also arose that police might now find it easier to persuade the public to support the use of surveillance technology and domestic drones. “After Boston,” Ryan Gallagher wrote this week in Slate, “the balance in the struggle between privacy and security may swing back in their favor.”

But research conducted shortly after 9/11, combined with some recent polling data, suggests that Americans may be unlikely to trade civil liberties for a greater sense of security as a result of the bombing. That’s because the attack hasn’t made the public significantly more fearful of future domestic terrorism, and because trust in government is low.

After 9/11, concern over terrorism skyrocketed. In a Gallup survey fielded in the days before the attack, less than one-half of one percent of Americans said terrorism was the country’s most important problem. But in October 2001, 46 percent did. These worries boosted support for legislation, such as the USA PATRIOT Act, that expanded law enforcement’s power to investigate suspected terrorism, even as those measures were criticized for eroding civil liberties protections.

In a survey conducted between November 2001 and January 2002, political scientists Darren Davis and Brian Silver designed a series of questions to explore the tradeoffs between security and civil liberties. They began by asking people whether they agreed more with the statement that “in order to curb terrorism in this country, it will be necessary to give up some civil liberties” or that “we should preserve our freedoms above all, even if there remains some risk of terrorism.” Forty-five percent of Americans chose the first option, indicating a willingness to give up some freedoms in exchange for greater security.

When respondents were asked about the tradeoffs involving specific measures, there was wide variation. Davis and Silver found that very few Americans – eight percent – believed that the government should have the power to investigate people who participate in nonviolent protests. And just 18 percent said they supported racial profiling. But when asked, for instance, whether they agreed that “high school teachers have the right to criticize America’s policies toward terrorism” or that “high school teachers should defend America’s policies in order to promote loyalty to our country,” 60 percent said teachers should back the government.

Perhaps not surprisingly, the biggest influence on whether people were willing to offer pro-security over pro-civil liberties responses was their fear of a second attack. Respondents who believed another terrorist act was imminent were more likely to support tradeoffs in favor of security. Importantly, Davis and Silver found that the relationship was strongest among people who expressed high levels of political trust: People who believe the government typically does the right thing and who were fearful of another terrorist attack were the most willing to relinquish civil liberties protections.

Those findings are consistent with a seriesofstudies by Stanley Feldman, Leonie Huddy and their colleagues at Stony Brook University. In one survey conducted between October 2001 and March 2002, the researchers found that 86 percent of Americans said they were “very” or “somewhat” concerned about another domestic terrorist act. The greater the concern, the more likely respondents were to support the use of government-issued ID cards and allowing authorities to monitor phone calls and e-mail.

But in contrast to 9/11, polling since the Boston Marathon suggests that the bombing has made Americans only slightly more fearful of future terrorist attacks than they were beforehand. Fifty-eight percent of respondents in a Pew poll conducted April 18-21 said they were “very” or “somewhat” worried about another attack on the United States. That was no higher, however, than when the same question was asked in November 2010. And it was significantly lower than the 71 percent who said they were worried in October 2001.

A slightly different question in a Washington Post poll taken April 17-18 found that 69 percent of Americans said that the possibility of a major terrorist attack worried them either “a great deal” or “somewhat.” That figure was only a few percentage points higher than when the same question was asked in 2007 and 2008.

In addition, political trust is lower today than it was in 2001, when public confidence in government rose sharply after the terrorist attacks. If Davis and Silver’s findings are correct, then greater skepticism of government – produced in part by the struggling economy – should limit the public’s willingness to give law enforcement more latitude.

Ultimately, the scope of the Boston tragedy was smaller than 9/11, which could help explain its limited effect on the public. It may also be that because Americans believe terrorist attacks are now a fundamental part of life in the United States, any single event will have a more muted effect on public opinion. And because the Tsarnaev brothers have not been connected to any known terrorist organizations, Americans may feel less under siege than they did when al-Qaeda and Osama bin Laden were identified as the perpetrators of the 2001 attacks.

Regardless of the reason, all of this suggests that policymakers are likely to face a more difficult task than they did after 9/11 in persuading the public to support additional security measures that infringe on Americans’ freedoms.